Primate-Secondary city relationships in mega city-regions: regional integration through urban network externalities


  • Jun Wen Delft University of Technology
  • Sylvia Jansen Delft University of Technology
  • Harry van der Heijden
  • Simin Yan Heidelberg University
  • Peter Boelhouwer Delft University of Technology


Secondary cities, primate cities, regional integration, mega city-region, urban network externalities




In Europe and China, the growth of secondary cities is reported to surpass that of primate cities due to factors such as urbanization policies, environmental concerns and considerations for life quality. Primate cities are the largest cities in a country or region, while secondary cities are cities that are second to primate cities in the urban hierarchy. While essential for regional development and national economic performance, secondary cities encounter challenges such as limited industrial and talent attraction compared to primate cities and insufficient political influence in shaping national policies. To address these challenges, scholars propose a strategic approach: cohesive integration through city networks, where secondary cities integrate with adjacent cities at the regional level.  This paper adopts the regional level of mega city-regions, where secondary cities experience both positive influences (borrowed size) and negative influences (agglomeration shadow) from primate cities through regional integration, and simultaneously act as the regional centers of adjacent small cities.

While existing studies mainly focus on analyzing the effects of regional integration quantitatively, qualitative insights into the integration process of secondary cities are lacking, especially the cooperation with primate cities. To address this gap, this study aims to qualitatively explore how the relationship between primate cities and secondary cities is formed in the process of regional integration. The theory of urban network externalities asserts that cities in networks apply economies of scale through complementary relationships and synergies in cooperative activities. Building upon this framework, this study 1) explored the preconditions for network participation, including seriousness, adaptability, and openness, and 2) further concluded the three levels of goals which guide cities' engagement in the network, including efficiency, synergy, and competence. We selected the notable case of the Yangtze River Delta city-region for the field study, and interviewed 30 urban planners, officials and academics in the one primate city (Shanghai) and four secondary cities in this region.

Preliminary findings indicate:

1) Preconditions and goals are related to national and regional development stages, economic status and policy orientations.

2) Efficiency goals dominate in various cooperation between secondary cities and primate cities, especially between cities with development disparities. Cooperation driven by efficiency goals may shift with changing developmental stages of secondary cities.

2) Synergy goals emerge among cities sharing similar markets, relying on resources such as geographical proximity and competitive industries. This fosters a strong cooperative relationship between primate cities and secondary cities, emphasizing demand allocation over competition.

3) Competence goals, regarded as the most strategic aim, involve collaborative efforts with cities facing similar challenges. However, these challenges might bring about conflicts in the distribution of resource and interests among primate cities and secondary cities.

This study provides nuanced insights into the dynamics of primate and secondary city relationships, contributing to a deeper understanding of the regional integration process of secondary cities in mega city-regions.


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